14.1.3積的乘方ppt

1、 積的乘方14.1.3 積的乘方探究填空,看看運(yùn)算過(guò)程用到哪些運(yùn)算律?運(yùn)算結(jié)果有什么規(guī)律?(1) (ab)2=(ab) (ab)=(aa) (bb)=a( )b ( );(2) (ab)3= _ = _ =a ( )b( ).思考： (ab)n=？14.1.3積的乘方ppt練習(xí)計(jì)算： (ab)4 ; (2) (-2xy)3; (3) (-3102)3 ; (4) (2ab2)3. a4b4 ; (2) 8x3y3;(3) 2.7107; (4) 8a3b6.練習(xí)計(jì)算： (ab)4 ; (2) (-2xy)3; (3) (-3102)3 ; (4) (2ab2)3. a4b4 ; (2) 8x3

2、y3;(3) 2.7107; (4) 8a3b6.練習(xí)計(jì)算： (ab)4 ; (2) (-2xy)3; (3) (-3102)3 ; (4) (2ab2)3. a4b4 ; (2) 8x3y3;(3) 2.7107; (4) 8a3b6.思維延伸已知,xm= ,xn=3.求下列各式的值：(1)x m+n; (2) x2mx2n; (3) x 3m+2n.解： (1) x m+n=x mx n= 3= ; (2) x2mx2n=(x m )2(x n)2=( )232= 9 = ; (3) x 3m+2n=x3mx2n=(x m)3(x n)2=( )332 = 9 = 對(duì)于任意底數(shù)a,b與任意

3、正整數(shù)n,(ab)n= (ab)(ab)(ab) = a a a b b b = a n b n. n個(gè)abn個(gè)an個(gè)b14.1.3積的乘方ppt一般地,我們有(ab)n=anbn(n為正整數(shù))即積的乘方,等于把積的每一個(gè)因式分別乘方,再把所得的冪相乘.14.1.3積的乘方ppt例3 計(jì)算: (1) (2a)3 ; (2) (-5b)3 ; (3) (xy2)2 ; (4) (-2x3)4.解: (1) (2a)3=23a3 = 8a3； (2) (-5b)3=(-5)3b3=-125b3； (3) (xy2)2=x2(y2)2=x2y4； (4) (-2x3)4=(-2)4(x3)4=16x12.練習(xí)計(jì)算: (ab)4 ; (2) (-2xy)3; (3) (-3102)3 ; (4) (2ab2)3. a4b4 ; (2) 8x3y3;(3) 2.7107; (4) 8a3b6.思維延伸已知,xm= ,xn=3.求下列各式的值:(1)x m+n; (2) x2mx2n; (3) x 3m+2n.解: (1) x m+n=x mx n= 3= ; (2) x2mx2n=(x m )2(x n)2=( )232= 9 = ; (3) x 3m+2n=x3mx2n=(x m)3(x n)2=( )3